Currently, I have an Excel Workbook saved as a Shared Document to a central
server, which allows multiple users to make changes and updates to their
respective tabs simultaneously as other users update thiers. This eliminates
the need to people to open as Read-only and wait for individuals to exit the
document.

I have be thinking about creating a SharePoint site and moving the document
to it, however, am concerned that SharePoint does not allow multiple users
into a Shared Document. I currently have Office XP and right now only one
individual can access the workbook and make changes. I have not been able to
find any literature that suggests that Office 2003 is any different.

2 Questions:
1-Is this available with Office XP? Am I doing something wrong with
importing documents? Can a Shared Excel Workbook function the same in
SharePoint as on a Server?
2-If the function is not available in Office XP, does Office 2003 offer
something similar?

Any suggestions to my issue? Thanks.